Synthesis and structure of sodium phenylsiloxanolate

Two different synthetic routes for the formation of sodium phenylsiloxanola te (SPS) have been developed: (i) the cleavage of oligo(phenylsilsesquioxan e), OPSSO, by NaOH in n-butyl alcohol and (ii) the reaction of phenyltri-n- butoxysilane, PhSi(n-BuO)(3), and NaOH in n-butyl alcohol in the presence o f water. From both reactions, (i) and (ii), crystalline sym-cis-{(Na+)(4)-[ PhSi(O)O-](4)}. 8n-BuOH (A) was the product isolated and characterized by X -ray diffraction. Reaction of SPS with Me3SiCl resulted in the formation of the corresponding sym-cis-tetraphenyltetrakis(trimethylsiloxy)cyclotetrasi loxane, [PhSi(O)OSiMe3](4). Under anhydrous conditions, PhSi(n-BuO)(3) and NaOH(-)reacted to give sodium phenyldi-n-butoxysilanolate, PhSi(ONa)(n-BuO) (2). Subsequent treatment with Me3SiCl led to the formation of phenyl(trime thylsiloxy)di-n-butoxysilane, PhSi(n-BuO)(2)(OSiMe3).